Tuesday is when I am least happy. It's a Tuesday Trough. There's not a lot in it, but it's statistically significant.
I am not alone. This graph shows the same data, but across the hundreds of thousands of people taking part in the Mappiness project:
It may be obvious, but the data 'proves' it: Tuesdays are the new Mondays.
I hope Mappiness goes on to draw even more startling conclusions. But this is a good start.
The obvious question is: why are Tuesdays less-fun than Mondays? My theory: the warm glow of weekends leaks into Mondays a bit.